scholarly journals Evaluation of Yeast Potential in the Biological Control of Colletotrichum orbiculare in Cucumber

2020 ◽  
Vol 12 (10) ◽  
pp. 295
Author(s):  
Renata F. Barabasz ◽  
Rayssa H. da Silva ◽  
Monica C. Sustakowski ◽  
Odair J. Kuhn ◽  
Jeferson C. Carvalho ◽  
...  
Keyword(s):  
Biological Control ◽  
Cell Suspension ◽  
Volatile Compounds ◽  
Culture Filtrate ◽  
Rhodotorula Glutinis ◽  
Pichia Guilliermondii ◽  
In Vivo Test ◽  
Conidia Germination ◽  
Severity Of The Disease

This work aimed to evaluate the effect of the yeasts Candida albicans, Pichia guilliermondii, Rhodotorula glutinis, Saccharomyces cerevisiae and Zygoascus hellenicus in the control of anthracnose in cucumbers. The influence of volatile and non-volatile compounds on mycelial growth and the effect of cell suspension and culture filtrate on conidial germination were evaluated. In a greenhouse, yeasts were tested on cucumber cotyledons, one cotyledon being treated and the other not; afterwards both cotyledons were challenged with C. orbiculare. The severity of the disease in both cotyledons was assessed by determining biological control and resistance induction. The production of volatile compounds from the yeasts R. glutinis and C. albicans reduced the pathogen growth by 90.7 and 90.0%, respectively. The production of non-volatile compounds stimulated the pathogen development. Conidia germination was affected when exposed to cell suspension of all tested isolates, ranging from 43 to 75%. For the culture filtrate from Z. hellenicus, it reduced the conidia germination by 11.4%. In the in vivo test, on the treated cotyledon, the yeasts Z. hellenicus, R. glutinis and S. cerevisiae reduced the anthracnose severity by 52.5, 50.0 and 42.5%, respectively.

scholarly journals Biological control of Ralstonia solanacearum (Smith), the causal pathogen of bacterial wilt disease by using Pantoea spp

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Kamal A. M. Abo-Elyousr ◽  
Sabry A. Hassan
Keyword(s):  
Biological Control ◽  
Cell Suspension ◽  
Disease Severity ◽  
Culture Filtrate ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Wilt Disease ◽  
Nucleotide Sequence Analysis ◽  
Tomato Root

Abstract Background Bacterial wilt of tomato (BWP) caused by Ralstonia solanacearum (Smith) is a very important disease. Biological control of this disease is a very important tool to protect the plant and environment from pollution of chemical control. Results Twenty isolates of genus, Pantoea were isolated from healthy tomato root. Out of 20 isolates, 2 strains, PHYTPO1 and PHYTPO2, showed highly antagonistic property to control the growth of R. solanacearum in vitro conditions. They were identified as P. agglomerans by using 16S rRNA nucleotide sequence analysis. The 2 isolates were selected to study their effect (as cell suspension or culture filtrate) on the bacterial wilt under greenhouse conditions. PHYTPO1 inhibited maximum growth reduction of R. solanacearum and formed 2.5 cm2 of inhibition zone, followed by 1.2 cm2 in PHYTOPO2 under in vitro conditions. Treating with both isolates of P. agglomerans was significantly reduced disease severity of tomato wilt disease. The disease severity was reduced to 74.1 when treated as cell suspension, while when treated as culture filtrate, it reduced the disease severity up to 69.4 than infected control. Conclusion The strains of Pantoea can be used as an ecofriendly method to control of the most economic pathogen of tomato under greenhouse conditions. Further study is needed to find an appropriate formulation and approving application of these bacteria under field conditions.

scholarly journals Yeast Potential for the Biological Control of Colletotrichum musae

2020 ◽  
Vol 12 (10) ◽  
pp. 301
Author(s):  
Claudineia B. Rodrigues ◽  
Renata F. Barabasz ◽  
Rayssa H. da Silva ◽  
Monica C. Sustakowski ◽  
Odair J. Kuhn ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Mycelial Growth ◽  
Rhodotorula Glutinis ◽  
Cryptococcus Laurentii ◽  
Post Harvest ◽  
Progress Curve ◽  
Antifungal Action ◽  
Colletotrichum Musae

One of the factors that cause the greatest loss of fruit in post-harvest are diseases, especially rotting such as anthracnose. Therefore, this work aimed to test the potential of the yeasts Candida albicans, Pichia guilliermondii, Rhodotorula glutinis, Saccharomyces cerevisiae, Cryptococcus laurentii and Zygoascus hellenicus in the control of Colletotrichum musae in bananas in post-harvest period. To test the potential of these yeasts, the effect of volatile and non-volatile compounds, culture pairing and spore germination of the fungus C. musae in vitro was evaluated. In post-harvest fruits, the area below the mycelial growth curve (AACCM) and the area below the disease progress curve (AACPD) were evaluated. The yeasts C. albicans, R. glutinis, S. cerevisiae and P. guilliermondii produced volatile compounds with antifungal action, reducing the development of the fungus in vitro. The yeast R. glutinis was shown to be more efficient in reducing mycelial growth in vitro of the fungus through the production of non-volatile compounds. The yeasts C. albicans and P. guilliermondii showed the presence of an inhibition halo. All yeasts induced the germination of C. musae conidia and were not efficient in controlling anthracnose in vivo.

scholarly journals BIOCONTROLE DA PODRIDÃO VERMELHA DA RAIZ E PROMOÇÃO DE CRESCIMENTO DA SOJA

Nativa ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 629
Author(s):  
Janaina Silva Sarzi ◽  
Juliane Ludwig ◽  
Jéssica Emília Rabuske ◽  
Pâmela Pires Ferst ◽  
Jéssica Malescki ◽  
...  
Keyword(s):  
Glycine Max ◽  
Fusarium Solani ◽  
Root Rot ◽  
Culture Technique ◽  
Trichoderma Spp ◽  
In Vivo Test ◽  
Crop Development ◽  
Severity Of The Disease

A soja é uma das principais culturas do agronegócio mundial, e o Brasil se destaca por ser um dos maiores produtores dessa leguminosa. As doenças, especialmente causadas por patógenos habitantes do solo interferem significativamente no desenvolvimento e produtividade da cultura, especialmente por serem de difícil controle. O objetivo desse trabalho foi avaliar o biocontrole de Fusarium solani agente causal da podridão vermelha da raiz na soja, por isolados de Trichoderma spp. Para isso, foi avaliado o efeito dos antagonistas in vitro sobre o patógeno, utilizando a técnica de cultivo pareado, e o potencial dos antagonistas em reduzir a severidade da doença causada por F. solani in vivo, por meio da inoculação do patógeno em sementes de milho e o tratamento do solo com os antagonistas. Pôde-se observar que dentre os isolados de Trichoderma spp., T. asperellum foi o mais eficiente em inibir o crescimento in vitro do patógeno. No ensaio in vivo, o uso de Trichoderma mostrou-se efetivo no controle da severidade da podridão vermelha da raiz na soja, sendo T. harzianum UFFS o mais eficiente na redução dos sintomas causados por F. solani, bem como, promover o crescimento de plantas de soja.Palavras-chave: Glycine max; Fusarium solani; Trichoderma. BIOCONTROL OF ROOT RED ROOT AND PROMOTION OF SOYBEAN GROWTH ABSTRACT: Soy is one of the main agribusiness crops worldwide, and Brazil stands out as one of the largest producers of this legume. Diseases, especially caused by soil-dwelling pathogens, significantly interfere in crop development and productivity, especially as they are difficult to control. The objective of this work was to evaluate the biocontrol of Fusarium solani causal agent of red root rot in soybean by isolates of Trichoderma spp. For this, the effect of in vitro antagonists on the pathogen, using the paired culture technique, and the potential of the antagonists in reducing the severity of the disease caused by F. solani in vivo, through the inoculation of the pathogen in seeds of corn and soil treatment with the antagonists. It was observed that among the isolates of Trichoderma spp., T. asperellum was the most efficient in inhibiting in vitro growth of the pathogen. In the in vivo test, the use of Trichoderma was effective in controlling the severity of red root rot in soybean, with T. harzianum UFFS being the most efficient in reducing the symptoms caused by F. solani, as well as promoting the growth of soybean plants.Keywords: Glycine max; Fusarium solani; Trichoderma.

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

Defibrotide Inhibits Platelet Activation by Cathepsin G Released From Stimulated Polymorphonuclear Leukocytes

1992 ◽  
Vol 67 (06) ◽  
pp. 660-664 ◽  
Author(s):  
Virgilio Evangelista ◽  
Paola Piccardoni ◽  
Giovanni de Gaetano ◽  
Chiara Cerletti
Keyword(s):  
Platelet Activation ◽  
Polymorphonuclear Leukocytes ◽  
Direct Interaction ◽  
Cathepsin G ◽  
In Vivo Test ◽  
Cell Functions ◽  
Test Models ◽  
Antithrombotic Effects

SummaryDefibrotide is a polydeoxyribonucleotide with antithrombotic effects in experimental animal models. Most of the actions of this drug have been observed in in vivo test models but no effects have been reported in in vitro systems. In this paper we demonstrate that defibrotide interferes with polymorphonuclear leukocyte-induced human platelet activation in vitro. This effect was not related to any direct interaction with polymorphonuclear leukocytes or platelets, but was due to the inhibition of cathepsin G, the main biochemical mediator of this cell-cell cooperation. Since cathepsin G not only induces platelet activation but also affects some endothelial cell functions, the anticathepsin G activity of defibrotide could help to explain the antithrombotic effect of this drug.

scholarly journals In Vitro and In Vivo Antifungal Activity of Sorbicillinoids Produced by Trichoderma longibrachiatum

2021 ◽  
Vol 7 (6) ◽  
pp. 428
Author(s):  
Men Thi Ngo ◽  
Minh Van Nguyen ◽  
Jae Woo Han ◽  
Myung Soo Park ◽  
Hun Kim ◽  
...  
Keyword(s):  
Late Blight ◽  
Culture Filtrate ◽  
Fungal Pathogens ◽  
Gray Mold ◽  
Trichoderma Longibrachiatum ◽  
Chemical Structures ◽  
Natural Agents ◽  
Blight Disease

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of Trichoderma longibrachiatum SFC100166 effectively suppressed the development of tomato gray mold, rice blast, and tomato late blight. The culture filtrate was then successively extracted with ethyl acetate and n-butanol to identify the fungicidal metabolites. Consequently, a new compound, spirosorbicillinol D (1), and a new natural compound, 2′,3′-dihydro-epoxysorbicillinol (2), together with 11 known compounds (3–13), were obtained from the solvent extracts. The chemical structures were determined by spectroscopic analyses and comparison with literature values. The results of the in vitro antifungal assay showed that of the tested fungal pathogens, Phytophthora infestans was the fungus most sensitive to the isolated compounds, with MIC values ranging from 6.3 to 400 µg/mL, except for trichotetronine (9) and trichodimerol (10). When tomato plants were treated with the representative compounds (4, 6, 7, and 11), bisvertinolone (6) strongly reduced the development of tomato late blight disease compared to the untreated control. Taken together, our results revealed that the culture filtrate of T. longibrachiatum SFC100166 and its metabolites could be useful sources for the development of new natural agents to control late blight caused by P. infestans.

Comparative Evaluation of In Vitro and In Vivo Assays for the Detection of Avian Infectious Bronchitis Virus as a Contaminant of Live Poultry Vaccines

1998 ◽  
Vol 26 (5) ◽  
pp. 629-634
Author(s):  
Emiliana Falcone ◽  
Edoardo Vignolo ◽  
Livia Di Trani ◽  
Simona Puzelli ◽  
Maria Tollis
Keyword(s):  
Infectious Bronchitis Virus ◽  
Serological Response ◽  
Avian Infectious Bronchitis Virus ◽  
Animal Testing ◽  
Rt Pcr ◽  
Pcr Assay ◽  
In Vivo Test ◽  
Infectious Bronchitis

A reverse transcriptase polymerase chain reaction (RT-PCR) assay specific for identifying avian infectious bronchitis virus (IBV) in poultry vaccines, and the serological response to IBV induced by the inoculation of chicks with a Newcastle disease vaccine spiked with the Massachusetts strain of IBV, were compared for their ability to detect IBV as a contaminant of avian vaccines. The sensitivity of the IBV-RT-PCR assay provided results which were at least equivalent to the biological effect produced by the inoculation of chicks, allowing this assay to be considered a valid alternative to animal testing in the quality control of avian immunologicals. This procedure can easily be adapted to detect a number of contaminants for which the in vivo test still represents the only available method of detection.

scholarly journals Wafer-Scale Fabrication and Assembly Method of Multichannel Microelectrode Arrays for ECoG Application

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 316
Author(s):  
Cong Wang ◽  
Yu-Chen Wei ◽  
Ho-Kun Sung ◽  
Alok Kumar ◽  
Zhong-Liang Zhou ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Electrochemical Impedance ◽  
Microelectrode Arrays ◽  
Absence Seizure ◽  
Curing Conditions ◽  
Wafer Scale ◽  
In Vivo Test ◽  
Assembly Method ◽  
Signal Recording

High density electrocorticography (ECoG)-based microelectrode arrays (MEAs) are fabricated to timely record the neural activities to provide the fundamental understanding in neuroscience and biomedical engineering. This paper aims to introduce a device-based concept and wafer-scale fabrication process for MEAs. Flexible and biocompatible polyimide is applied on MEAs to bear all possible stress and strain. Detailed fabrication key techniques, including surface treatment, polyimide stability measurement, evaporation process, and curing conditions, have been discussed thoroughly. Moreover, the fabricated polyimide-based MEAs are surface-mounted on well-packaged printed circuit boards (PCBs) via a slot-type connector without any additional wire bonding to make the signal recording process easier. An absence seizure was recorded during the in vivo test, which shows the availability of signal recording based on the presented MEAs. The proposed MEAs could be remained at the skull, while the connector and PCBs can be disassembled apart. Therefore, the testing sample will get less suffering. To verify the robustness of the fabricated MEAs, the impedance properties were characterized using electrochemical impedance spectroscopy. The measured results indicate an average impedance of 12.3 ± 0.675 kΩ at 1 kHz. In total, 10 groups of MEAs were sample tested, and over 90% of the total 60 channels per 1-MEAs operated efficiently.

scholarly journals Defect structures of sodium and chloride co-substituted hydroxyapatite and its osseointegration capacity

2021 ◽  
Vol 56 (9) ◽  
pp. 5493-5508
Author(s):  
Dong Su Yoo ◽  
Jung Sang Cho ◽  
Yong-Chae Chung ◽  
Sang-Hoon Rhee
Keyword(s):  
Binding Energies ◽  
Dissolution Behavior ◽  
Total System ◽  
Carbonate Apatite ◽  
In Vivo Test ◽  
Co Substitution ◽  
Constituent Elements ◽  
Low Crystalline ◽  
Charged Point

AbstractA defect structure and osseointegration capacity of sodium and chloride co-substituted hydroxyapatite (NaClAp) were newly studied. The NaClAp was prepared by reacting H3PO4 and Ca(OH)2 with NaNO3 and NH4Cl followed by sintering; pure hydroxyapatite (HAp) was synthesized as a control. After sintering, the co-substitution of Ca and OH with Na and Cl, respectively, produced charged point defects at Ca and PO4 sites. Also, OH molecules partially adopted a head-on structure. The calculated total system energy of NaClAp was higher, whereas the binding energies between each constituent elements and system were lower than those of HAp. These results suggest that NaClAp was less stable than HAp, due to the formation of various defects by co-substitution of Na and Cl. Indeed, NaClAp exhibited higher dissolution behavior in simulated body fluid (SBF) compared with HAp. Accordingly, this increased the capability to produce low crystalline hydroxyl carbonate apatite, likely due to the increasing degree of apatite supersaturation in SBF. Besides, the NaClAp granules showed noticeable improvements in osseointegration capacity four weeks after in vivo test compared with HAp. Collectively, these results imply that the defects made by multiple ion substitutions are useful to increase osseointegration capacity of hydroxyapatite.

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